What's the context?
The industrial revolution
Even further back...
The agricultural revolution
Trade?
Communication?
Travel?
Exploration?
These things happened during the time of the Mexican Revolution. General Victoriano Huerta came after the assasination of Madero and Pino Suarez, but before that, Madero and Suarez were pushed to resign in 1913. The ouster of Huerta failed. The failure of Huerta's ouster resulted to a civil war.
Answer: One word=Power
Explanation:
The Soviet Union wanted power plus they were a communist country so they wanted to spread communism and at that time Americans were scared of Communism